Ngapuhi are being summoned to debate who has the mandate to negotiate the country's largest iwi's long-awaited Treaty of Waitangi settlement.
The Government says it recognises the mandate given to Tuhoronuku by 76.4 per cent of tribal members in 2011.
However, the issue is further splitting an already divided Ngapuhi, says kaumatua Kingi Taurua, who is inviting hapu to debate the issue at Te Tii Marae, Waitangi, on Saturday.
The Waitangi Tribunal is holding an urgent hearing into the granting of the Tuhoronuku mandate next week.
Treaty law expert Charles Hirschfield and other negotiation and law specialists would be at Saturday's hui.
Prime Minister John Key said in Kerikeri last week he had met with Te Runanga-a-Iwi o Ngapuhi chairman Sonny Tau in recent weeks and his Government accepted that the runanga-backed Tuhoronuku negotiation team had the people's mandate.
Mr Taurua said the majority of hapu might disagree with that view as well as the process that led to that outcome.
"Now the cat's out of the bag Ngapuhi has to come together and say what they want," he said.
Mr Taurua said there was widespread hapu support for the Waitangi Tribunal to hear and decide the mandate issue.
Mr Tau, however, has said the urgent Waitangi Tribunal hearing is "unnecessary and a waste of money" and would hold back Ngapuhi and Northland socially and economically.
The hearing would cost about $2 million, he said.
Mr Taurua believed Ngapuhi coming together to decide "once and for all" could speed up the settlement process.
"I'm asking for insight. We want to get one story right rather than every hapu having a different story," Mr Taurua said.
The hui will be from 9am on Saturday, "and into Sunday if that's what it takes".